| | 1. Hypanthium bell-shaped, < 2 mm; stem decumbent to erect, rooting at nodes |
| L. portula |
| | 1' Hypanthium cylindric, 4–7 mm; stem ascending to erect, rooting at base |
| |
| | 2. Stem branching at base; lower branches decumbent to ascending |
| |
| | 3. Hypanthium appendages awl-like, ± 1 mm, ± 2 × sepals |
| 2 L. hyssopifolia |
| | 3' Hypanthium appendages deltate, ± 0.5 mm, ± = sepals |
| L. tribracteatum |
| | 2' Stem branching at base or not, lower generally erect |
| |
| | 4. Inflorescence bracts ovate, acuminate; petals 8–14 mm; stem ± puberulent |
| L. salicaria |
| | 4' Inflorescence bracts linear, acute to obtuse; petals 2–8 mm; stem glabrous |
| |
| | 5. Lower leaves linear-lanceolate; pedicels 1–2 mm; sepals ± = appendages; petals 4–8 mm |
| L. californicum |
| | 5' Lower leaves elliptic to oblong; flowers sessile; sepals < appendages; petals 2–5 mm |
| 2 L. hyssopifolia
|